Method and apparatus for pumping fluids



A. G.-M. MICHELL.

METHOD AND APPARATUS FOR PUMPING FLUIDS.

APPLICATION man Auw. 1919.

l ,421 9716,l Patented July 4, 1922 2 SHEETS-SHEET 1.

A. G. M. MICHELL.

METHOD AND APPARATUS FOR PUMPING FLums.

APPLICATION FILED AUG-5.1919.

Patented July 4, 1922.

2 SHEETS-SHEET 2.

Y 2S b'aeb Y l-KN rrED STATE-s *Per ANTHONY G. MICEELL, OF MELBOURNE, VICTORIA, AUSTRALIA, ASSIGNOR, T0 MICHELL ABEAIIELIN GS LIMITED, 0F WESTMINSTER, ENGLAND.

METHOD IND APPARATUS FOR PUMPING FJUIDS.

To aZZ who/m, t may concern: y

Be it known that ANTHONY GEORGE MAL- DoN MIonnLL, a subject of the King of Great Britain, and resident of 450 Collins Street, Melbourne, in the State of Victoria, Commonwealth of Australia, has invented certain new and useful Improvements in Improved Methods. and Apparatus for Pumping Fluids, of which the followmg 1s a specliication.

According to this invention the improved method of pumping fluid consists in utiliz- -ing the viscous resistance which uid lms oppose to change of thickness by means effecting the cyclic variation of one or more narrow interspaces between relatively moving parts the fluid being admitted to the interspace or interspaces in the form of a thin lilm., K

During continuous motion of the walls of the interspace the thickness of the fluid film at any given point is cyclically varied causing generation of pressure in the film durin that phase of the cycle in which the thickness of the film is diminished.

The apparatus is of rotary type, and the relative motions of the parts by which the thickness of the Huid film is varied as above stated, is as far as possible ofthe nature of rolling rather than of shearing or sliding. By this means the generation of unnecessary Viscous'resistance 1n the fluid film is avoided, or minimized.

Although pumps operating by the viscosityof fluids are already known, (e. g. 'the vacuum pump for rarefled gases known as the Gaede pump described in British patent specification No. 27457/1909 and the means for effecting pressure-lubrication described in the present applicants Commonwealth Patent No. E38/16), hitherto considerable pressures have onlybeen generated by relatively rapid shearing or sliding motions whereby useless and deleteriousresistances have been produced in the fluid, and such pumps havebeen correspondingly inecient. One of the objects of the present invention is to render pumps of this class more economical in the appli- Specification of Letters Patent.

'being taken on the line in such appliances Patented July a, i922.

Application filed August 5, 1919. Serial No. 315,476.

multiple whereby the capacity of the pump 1s roportionately increased.

.n the drawings accompanying my provislonalspecilication two practical types of construction incorporating the invention are shown.

Fig. 1 is an axial, section of a pump of the first of these types, the section being taken along the radlal planes marked l", l", in Fig. 2. Y 2 comprises two partial transverse sectlons on planes marked 11a, 11", respectively in Fig. 1, each section showing onequarter of the pump.

1g. 3 is a transverse 'section of an alternative method of connecting the impelling element of the pump' to the driving spindle.

Fig. 4 is an axial section ofla pump 'according to the second t pe of construction,

V-IV of Fig. 5. Fig. 5 comprises a plan and partial transverse section on a plane marked V-V in g Fig; 4, each view showing one-half of the tively being concentric with the stator 3, 3,

The rotor 4 is furnished with several external flanges 9, which engage closely between corresponding internal flanges 10, formed on the stator halves 3, 3a. the langes 9, 10, is of slightly greater thickness at its root, where it is attached to the rotor or stator, than at its free or distal portion, the faces of the flanges thus forming portions of very flat cones. For thesake of clearness in the drawing, this variation of thickness, and also the clearance spaces 11, between the rotor-flanges and stator-anges andthe eccentricity of the eccentric 5 are greatly exaggerated. 4

The stator-Hanges 9-10 are formed with Each of a series of radial ducts 12, each communieating with ports 13 near the middle of the radial widths of the flanges, and also with longitudinal ducts 14, debouching through valves 15 into a circumferential canal 16,

which leads to the discharge-pipe 17 of the pump. Another series of longitudinal ducts, 18 formed through the stator-flanges 10 near their roots, supplies the fluid to be pumped from the space 19 'into the interspaces 11, whence the fluid is forced by the co-action Vof the rotor-flanges 9 and lstatorianges 10 into the ports 12. The intakebranch 20 admits the fluid from the external source of supply to the space 19 The rotor 4 being rotatably mounted on the eccentric 5, has its motion retarded by the viscosity of the Huid on the side where its Hanges 9 engage most closely with the flanges 10 of the stator 3, 3, and thus revolves with a kind of rolling motion, the successive parts of the rotor periphery engaging in turn with the various parts of the periphery of the stator 3, 3, and forcing oil successively through the various ports 13, ducts 12, 14 and valves 15.

The necessary quasi rolling motion of the rotor 4 with respect to the stator-element 3, 3a, may be imparted in'other ways than that shown in Figs. 1 and 2. For instance as shown in Fig. 3, the rotor 4 may be caused to move eccentrically in the stator (indicated by the dotted line 3), with a combined rotary and rolling motion by being connected to the driving-spindle 6, through a suitable coupling. As shown in Fig. 3 the coupling consists of a loose sleevev 21, connected with the spindle 6 and ro'tor 4, by sliding ins designated by- 22 and 23 respective y. The s eeve 21 is thus compelled to rotatev at high speed with the spindle 6, but the rotor 4 is free to assume an eccentric position under the action of centrifugal 'force, and to rotate on its moving axis, so as to perform the same kind of rolling motion `as already described in connection with Figs. `1 and 2. The 'construction shown in Fig.

3 is applicable not only to the pump illustrated in Figs. 1 and 2 but also to that shown in Figs. 4 and 5 which will now be described.v

In this form also, the pump comprises a i base-plate 1 and cover-plate 2, carrying bearings 7 and 8 respectively in which a spindle 6 revolves, formed with an eccentric 5. The stator 3 'which is a hollow-cylinder concentric .with the bearings 7 and 8, is provided with a series of radial ducts 12, communieating both with the delivery pipe 17 and intake pipe 20, through a series of delivery valves 15, and suction valves 24. The rotor element consists of a series of cylindrical sleeves, 25, 25", 25, 25, 25"', fitted within one another in succession, and the last within the stator 3, .with small clearances or interspaces (exaggerated in the drawing), and

bored with a series of radial ducts 26 near the middle of their lengths. They may also be provided with a series of longitudinal grooves 27, intersecting the holes 26. The sleeves 25a, 25", 25, 25d, 25e, and roller 30 described below, are prevented from rotating spect to one another and tothe stator 3 without rotating bodily. They are impelled to perform this motion by the pressure of the roller 30, rotatably mounted on theeccentric 5, which acts successively at the various parts of their peripheries. By the co-action of the sleeves 25a, 25h, 25s, 25d, 25e, with one another and with the inner surface of the stator 3, the iuid on account of its viscosity is drawn from the intake pipe 20,1suctionvalves 24, holes 12, 26, and rooves 27 to the interspaces 11 on one side o the pump, while fluid previously admitted to the interspaces 11, is forced by the same action from them through grooves 27, holes 26, 12, and delivery valves 15 on the other side to the discharge pipe 17.

It will be understood that the invention is not limited to the particular forms of pump hereinbefore described and illustrated, as it is evident that the means for cyclically varying the thickness of alfluid lm, which constitutes the basic principle, can be carried out in apparatus of other analogous forms.`

The essential character of the apparatus is the provision of closely fitting and co-acting surfaces which approach and recede from each other cyclically, so that a filmv of uid bounded by such surfaces is subjected to rapid defformations orvariations of thickness, whereby fluid pressure due to viscoslty -ari` generated in the film without excessivev shearing resistances.

Iclaim-' Y 1. A method of pumping consisting in cyclically varying the thickness of' a vfilm iof the iiuid .to be pumped between `closely fitting and relatively moving surfaces, whereby pressure, dependent on the viscous .resistance of the Huid, is generated in the film during the portion of the cycle in Ywhich the thickness of the film is diminished.' Y

2. A pump comprising a stationary element and a moving element having closely fitting opp'osed surfaces, means for. communicating an eccentric motion of small amplitude to the movi element, and valve-elements by which fluldis alternately admitted to and abstracted Afrom interspaces between the stationary and moving element.

1,421,976 ggg 3. A pump comprising an external staor interspaces, is cyclically varied at each tionary hollow cylinder one or more internal point of the circumference, and thev 'luid cylindrical sleeves, forming one or more therein subjected to cyclic alternations of 10 thin cylindrical interspaces, and a central pressure.

5 rotating element adapted to impart an ecl' centric motion to the inner or innermost A. G. M. MICHELL.

sleeve, whereby the width of the interspace 

